This ADAMHA RCDA (Level II) proposal describes a comprehensive research plan that will result in completion of an ambitious field project on social behavior. The specific aims and methodologies of the research are headed toward a modern characterization - in both proximate and ultimate terms - of the relationship of within family aggression, conflict, and cooperation to kinship asymmetries (arising from the alternative reproductive tactics of individuals) and the relationship of these variables to individual behavior, such as parental allocation tactics and dispersal of offspring, that may mediate and control individual social organization. The specific aims are: 1) to assess the degree of uncertain maternity and paternity using DNA-fingerprinting of blood and simple models of Mendelian genetics; 2) To evaluate the relationship of within family kinship to aggressive behavior of males and females; 3) To evaluate potential sources of variation, including resource abundance, previous history, hormonal condition, etc., in aggressive behavior of females and males; 4) To describe normal hormonal profiles of females and males during the breeding season and to experimentally manipulate hormonal condition using "challenge" tests; 5) To assess a possible counter-strategy to uncertain parentage, namely whether caregivers recognize kin versus nonkin eggs and nestlings; 6) To assess the patterns of gender interactions between caregivers and offspring; and 7) To evaluate the proximate and ultimate causes of natal and breeding dispersal. The achievement of these research objectives will establish this program as a major program in the study of social behavior. Research development plans include the establishment of collaborations with scientists whose technical skills are specific; the nominee intends to produce a series of papers and a monograph on the behavioral ecology of eastern bluebirds and several general papers on social behavior. The nominee's plans for other professional activities include involvement in professional societies in roles that directly affect her own research activities and those of others.